Design the retrofitting of a building found inadequate in the performance analysis in the same StatiCAD project file: define retrofitting for columns, beams, shear walls and infill walls, reassess the retrofitted building with a single option, and see the before–after comparison in the report.
Retrofitting in a single project
The seismic safety of a building retrofitted per TBDY 2018 is determined with the assessment principles given for existing buildings. In other words, retrofitting calculation is not a separate calculation; it is the repetition of the same performance analysis with the retrofitted members.
The code defines retrofitting at member and system level: wrapping columns with fiber-reinforced polymer, RC or steel, enlarging the column section (jacketing), wrapping beams, new RC shear walls and retrofitting infill walls. Each method affects stiffness, strength and ductility differently; for example, wrapping methods do not increase the flexural capacity of the column, whereas jacketing does.
In StatiCAD, retrofitting is defined as a member property. With the “Include retrofitting in calculation” option off, the program calculates the existing state of the building, and with it on, the retrofitted state; stiffness, capacity, damage limits, building verdict and report are updated together.
Including member and system retrofitting in the calculation and reporting it, as corresponding to the code.
Retrofitting information is embedded in the performance report:
The relations of the retrofitting module, namely the Annex 15B confinement model, shear contributions, lap-splice check, jacket section properties and Annex 15C diagonal struts, have been compared numerically with independent calculations and hand calculations.
That, with the retrofitting option off, the results remain exactly identical to those of a building with no retrofitting defined is checked in every edition.
In columns, fiber-reinforced polymer wrapping, jacketing (section enlargement), RC jacketing and steel jacketing; in beams, fiber-reinforced polymer wrapping and external stirrups; in shear walls, fiber-reinforced polymer wrapping of the end region and new RC shear walls; in infill walls, steel-mesh reinforced plaster and fiber-reinforced polymer diagonal strips.
No. Retrofitting is stored in the same project as a member property. With the “Include retrofitting in calculation” option off, the existing building is calculated, and with it on, the retrofitted building; the comparison of the two states can be put on the first page of the report.
Per TBDY 2018, wrapping methods (fiber-reinforced polymer, RC and steel jacketing) do not increase the flexural capacity of the column; they increase ductility and shear strength. Jacketing, since it enlarges the section, increases stiffness, flexural and shear strength together. StatiCAD accounts for each method with these differences.
Yes. The stiffness and section effects of fiber-reinforced polymer, jacketing, new shear wall and infill wall retrofitting are also reflected in the nonlinear pushover analysis. Additional shear checks such as steel jacketing, external stirrups and anchorage are reported in the linear assessment.
The calculation does not stop; the relevant condition appears as an error or warning row in the Project Checklist and is also shown in the summary in the property window. The final decision is made by the engineer.
Yes. In masonry buildings, retrofitting can be done with shotcrete, tie columns, fiber-reinforced polymer and new walls. See the Masonry Building Software page for details.
Download the demo version and try before and after retrofitting assessment on your own project for free.